The objective of this research project is to explore how the outcomes and stability of cohabiting unions are related to life course experiences and attitudes. Two related questions will be investigated: 1) are cohabiting unions formed at the same time as the experience of a life course event (looking at events such as fertility, employment, education, residential mobility) related to the likelihood the cohabitation transitions into marriage or breaks up and, if a marriage occurs, to the likelihood that the marriage remains intact; and 2) are attitudes held prior to the formation of a cohabitation predictive of whether the union will transition into marriage or break up and, if a marriage occurs, of the stability of the marital union. The main hypotheses are 1) the likelihood of a cohabiting union breaking up, staying intact, or transitioning into marriage and whether the subsequent marriage remains intact will vary by whether the union was formed at the same time other life course events were experienced, what kind of events, and the number of events as well as vary by marital status and race/ethnicity; and 2) the cohabiting unions of individuals with more traditional value orientations and who are more religious are more likely to transition into marriage, and their subsequent marriages are more likely to be stable compared to less traditional persons. Multinomial logistic regression and event history methods will be applied to Waves 1, 2, and 3 of the National Survey of Families and Households to model union transitions. This research will advance our understanding of how cohabitation fits into the American family system.